US2321509A - Electric sadiron - Google Patents

Description

June s; 1943.

B'. G. oLvlNG y 2,321,509

ELECTRIC SADIRON I Filed Sept. 18. 1941 2 Sheets-Sheet 1 l ATTORNEY June 8, 1943. Egg, oLvlNG v 2,321,509

A I ELECTRIQ SADIRoN I Filed sept. 1s, 1941 2 sheets-sheet 2 ATTURNEY Patented June 8, 1943 2,321,509 ELECTRIC SADIRON Bror G. Giving, Elgin,

Electric Company, El

Delaware Ill., assignor to McGraw gin, lill., a corporation of Application September 18, 194i, Serial No. 411,304

(Cl. SS-W) 4 Claims.

My invention relates to electric sadirons. The main object of my invention is to provide an electrically heated sadiron comprising means for maintaining the temperature of the cover at a relatively low value.

Another object of my invention is to provide an electric sadiron in which .the cover is-so designed and constructed as to operate at a relatively low temperature either during actual use thereof or during the periods of non-use thereof when set up on its heel rest.

Another object of my invention is to provide heat-dissipating means closely associated with the cover to reduce the temperature of the cover during the time that the electric heating element of the iron is energized, said heat-dissipating means being useable also as a heel rest.

Other objects of my invention will either be apparent from a description of one form lof electric sadiron embodying my invention or will be pointed out in the course of such description and set forth in the appended claims.

In the drawings,

Figure 1 is a top plan view of an electric iron embodying my invention,

Fig. 2 is a longitudinal vertical-sectionalview through such an iron,

Fig. 3is a vertical cross-sectional view thereof taken on the line 3 3 of Fig. 2.

Fig. 4 is a view in rear elevation of an iron embodying my invention, and,

Fig. .5 is a view in side elevation showing the iron on its heel rest.

The tendency of recent years in the design of electric sadirons has been tolincrease the amount of energy which is to be translated intoy heat by the heating element of an electric sadiron and since there are relatively well dened limits as to the size of such irons, there has been a tendency for the cover of such irons to operate at relatively high temperatures.v It isof course, obvious that a stable condition as to the temperature of the cover of a sadiron will be estab lished when the amount of heat radiated or otherwise disposed of or lost by the cover equals substantially the amount of heat received by said cover. One of the attendant circumstances of interest in this desired ilxation of a relatively low temperature in the cover is rst to reduce the amount of heat which reaches the cover, either by conduction, by convection currents of heated air or by radiation from the heated body. Folspaces and I may use a mixture lowing this another important element is that of providing means to dissipate whatever heat is actually received in the aforesaid dierent ways l5 bythe cover 'and it will be noted from the drawings and the description thereof that I have constructed an electric iron embodying such means.

I have shown an electrically heated sadiron II as comprising a sole-plate I3 which may have a recessed upper face adapted to receive an electrically-insulated electric heating element I5 which may be of the usual or desired kind and may be constructed, for illustrative purposes only, to include an upper and a lower sheet of mica having placed therebetween a third sheet of mica having a resistor wrapped therearound, allA as now well known in the art. My iron may include also a top or clamping plate Il and any suitable or desired means for ensuring close engagement between the soleplate I3 and the heating element I6 may be used, plate I1 tightly heater I5. The considered to constitute the heated body hereinparticularly in holding the top against the upper surface of after referred to.

I provide a `novel form of 4cover I9 which, as shown in Figs. 2 and 3 of the drawings, is made relatively thick in contradlstinction to the usual cover or shell of relatively thin sheet metal. I prefer also to ,make the cover I9 of a metal or metal alloy having high heat conductivity for a purpose which will hereinafter appear. The general shape of the cover I9 is along relatively standard lines at the front portion and of substantially the .main part of its length but I prefer to have the rear end portion 2i extended beyond the rear end portion of the heated body. Terminal leads 23 of the heating element I5 may extend beyond the rear end of the heated body and be connected with terminals 25, only one of which is shown in the drawings.

In order to reduce the amount of heat reaching cover I9 from the heated body I nrst of all provide a mass 21 of a suitable heat insulating material particularly resistant to high temperature and therefore having a multitude of minute air of material, wool, glass and diatomaceous earth. `I may state that I prefer such a mixture but may also use other materials such as magnesia carbonate, rock wool. glass wool or other similar typesof heat insulating material. At present I prefer the rst named mixture because of its high thermal resistivity combined with a relatively high resistance to accidental -impact and its ilexibility.

'The support for the cover may include a pair of supporting brackets 2l and II which may be o! substantially U-shape in general outline, the

elements I3, I5 and I1 may be I 2 j lower end portions being heat-insulatedly mounted on the top plate I1. For this purpose I may use a short machine screw 33 adapted to have screw-threaded engagement with the top plate, washers of heat-insulating material being placed between the end portions of the supports 29 and `3I and the `top plate as well as the securing screw 33. The intermediate 'portion of the members 29 and V3| maybe .secured against the under surface of the mid portions of the cover as by short machine screws 31. lIt will be noted that the actual area'of engagement between the bracket supportingl members' 29 and 3| and the inside surface of the coverl isl made relatively small whereby the thermal reluctance of the heat flow path from the top plate I1 to the cover I9 is made relatively high.

I may further point out here that the cover is supported in the manner shown in the drawings and described above out of contact with the heated body and particularly with the soleplate I3.

I provide further a plurality of fins 39 which are' preferably made integral with the rear end portion of the cover I9 and I wish to point out that, referring particularly to Fig. 2 of the drawings, the normal lower edges of the ilns 39 are open or unobstructed as regards the ow of cooling air between the spaced fins 39. It is to be noted further thatthe upperor combination rear and partially arcuate upper surfaces of the fins 39 are also free and unobstructed so that any convection currents of air will follow substantially the normal path, namely, upwardly, as shown by the arrow 4 I, during all the time that the iron is in its normal ironing position, shown in Fig, 2 of the drawings, either while it is stationary, as may occur for a short interval of time, or while it is being moved forward and backward as in ironing.

I wish to point out also that a part of the forward edge surfaces of the ns 39 is also open and unobstructed, this portion being indicated by numeral 43, in Fig. 2 of the drawings.

In order to provide a. surface adapted to be engaged with the rear end 'portion of a handle 45, the fins 39 are united at their upper lefthand edges, as is shown by element 41, the inclined rear end portion of the handle 45 being secured against member 41 by screws 49. The

'front end portion of handle 45 ends in a depending supporting member BI'adapted to engage the outside surface of the front portion of cover I9 andbe held thereaginst by a screw 53.

One or more of the intermediate fins are provided with extensions 55 projecting outwardly beyond the limit of the ns 39, these projections being located near the upper ends of the f'lns. I provide also projections 51 near the lower end of the outermost or limiting fins 59 near the lower end thereof so that the two pairs of projections 55 and 51 will cooperate to constitute a heel rest for the iron.

I have illustrated in Figs. l and 4 of the drawings one method of bringing out a twin conductor cord 6I at the rear end of one side of the iron and I may use an elongated rubber bushing 53 properly secured to the housing to protect the cord 59, all in a manner well known in the art. `It is to be understood that the inner ends of the cord 59 are connected to the terminal members 25,

I have shown, generally only, a thermostatic control switch 65 mounted on the top plate I1 and embedded in and covered by the mass 21 of heat-insulating material. An upwardly extendsubstantially asv the spaced ns surface of mass 21, cooling lng rod 61 is mechanically connected with the thermally-controlled switch 65 and may be adjusted'by Van arm 69 to set the temperature at which the thermally-controlled switch 65 will open the heater circuit.

As is evident from Fig. 2 of the drawings, the .path of the coolingair normally flowing between Y has a relatively large proportion of the total peripheral area of the outer edges of therflns open and unobstructed so that a relatively large amount of air will flow upwardly. I have illustrated by arrow 1I the path of air flowing between the ns while the iron is' moved forwardly and it is obvious, of course, that air will flow in a substantially horizontal path when the iron is moved backwardly, this flow of air leaving the spaces between the fins at part 43.

Referring to Fig. 5 of the drawings Il have illustrated, generally only, the path of flow of the cooling air between the fins when the iron is placed on its heel rest and since the cover I9 is' spaced anA appreciable distance from the upper air will also flow in the space between mass 21 and the inside surface of cover I9.

I have already stated that I prefer to use a metal or an alloy having high heat conductivity and-for illustrative purposes I prefer to use aluminum or copper. I further prefer to make the fins integral with the relatively heavy cover and one method of doing this is by the so-called die casting method.

I may also roughen the surface of the fins whereby the heat-dissipating effect of the fins in combination with the convection currents of air hereinbefore referred to, is materially increased, The amount of heat radiated by the outermost roughened surfaces of the fins is also appreciably increased by the roughening of the surface thereof. It will thus be noticed that I first of all provide a sadlron structure in which the amount of heat reaching the cover from the heated body is greatly reduced and further in which the cover is provided with means of a heat-dissipating nature at a part thereof away from and preferably in the rear of the heated body for drawing heat from the cover and dissipatingit into the ambient atmosphere during usey or non-use of the iron. Various modifications may be made in the structure embodying my invention and all such modifications clearly coming within the scope of the appended claims are to be considered as being covered thereby.

I claim as my invention:

1. An electric iron comprising a heated body, a relatively thick metallic cover thereover spaced from the body and having integral therewith and extending over and beyond the rear end portion of the cover a plurality of spaced heat-dissipating fins extending substantially at right angles relatively to the outer surface of the cover, the spaces between the :Iins being open over the major portion of their outer periphery and at their front vedges to cause a current of cooling air to flow between said fins and cool said cover.

2. An iron as set forth in claim 1 in which certain of the ns have projecting lugs thereon spaced from each other and cooperating to form a heel rest for said iron.

3. An electric iron comprising a heated body, a cover thereover spaced therfrom and having secured thereto an air cooled heat-dissipating means comprising a plurality of normally vertimay state that I caemos l 3 dle having its iront end portion secured to the cover and a plurality oi' vertical heat-dissipating ilns secured to the rear end portion of the cover to overlap the rear end portion and' extend rearwsrdly thereof and means directly securing the l rear end portion of the handle to said plurality oi' dns. BROR. G. OLVING`

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